Here are the seven movies on the Writer's Guild of America top 101 movies list that I haven't watched before:
8 1/2 (1963): A movie about making a movie. Not my cup of tea.
Adaptation (2002): A movie about writing a movie. Interesting to watch, but also not really my cup of tea.
Being John Malkovich (1999): Such a weird, weird movie.
Crimes and Misdemeanors (1989): I still don't get why anybody likes Woody Allen movies.
Eternal Sunshine of the Spotless Mind (2004): Not really my cup of tea, but certainly an interesting movie.
Memento (2000): I see why this is considered well written. It certainly wouldn't be easy to construct.
Sweet Smell of Success (1957): Not a fan.